The present invention relates generally to headlamp adjustors which are used to adjust the position of a reflector of a headlamp assembly, and relates more specifically to a headlamp adjustor which includes a selftapping drive screw.
The present invention also relates generally to methods for adjusting the position of a reflector of a headlamp assembly, and relates more specifically to a method for adjusting the position of a reflector of a headlamp assembly where the method includes a step of rotating a drive screw to form a thread or worm gear and effect rotation of said worm gear to attain a change in the position of the reflector.
The present invention also relates generally to methods for making headlamp adjustors, and relates more specifically to a method for making a headlamp adjustor where the method includes a step of threading a worm gear using the initial engagement of the drive screw to form a mating thread on the worm gear that allows for operation thereof, and thereafter applying a retaining member to the drive screw.
Modern day headlamps for vehicles are engineered and designed to be aerodynamically efficient. In this regard, the headlamps are designed as sealed assemblies wherein the portion of the headlamp approximate the outer surface of the automobile is relatively stationary, and is aerodynamic.
A typical modern day headlamp assembly 12 is illustrated in a plan view seen as FIG. 1, and normally includes: a fixed housing 20, to which an outer headlamp lens 22 is affixed; a movable reflector 24, which is mounted within the fixed housing 20; and a stationary headlamp bulb (not shown), which is positioned within the movable reflector 24. Typically, the movable reflector 24 is mounted to the housing 20 by a universal or ball-type pivot 26 which is stationary, or fixed, on the housing 20.
A first pivot point 28 is disposed generally vertical of the fixed pivot 26, and a second pivot point 30 is disposed generally horizontal of the fixed pivot 26. As such, the movable reflector 24 may be pivoted about the fixed pivot 26 in the vertical and horizontal planes to aim the headlamp beam. Adjustment mechanisms, or headlamp adjustors, 40 and 42 are typically provided at the first and second pivot points, 28 and 30, normally termed the vertical pivot and the horizontal pivot, and the headlamp adjustors 40 and 42 can be operated to effect movement of the reflector 24 in the vertical and horizontal planes.
The headlamp adjustors 40 and 42 are typically mounted to the housing 20 of the headlamp assembly 12 and have adjustor output shafts 44, 46 operatively connected to the movable reflector 24 by ball and socket type pivots, or the like, such that linear movement of the adjustor output shafts 44, 46 produces pivoting of the movable reflector in the vertical and horizontal planes. Specifically, each headlamp adjustor 40, 42 typically includes drive structure 48, 50 for receiving a tool, and typically the drive structure 48, 50 is precision geared to the adjustor output shaft 44, 46. The gearing provides that using the tool to rotate the drive structure 48, 50 causes linear translation of the adjustor output shaft 44, 46 and therefore adjustment of the position of the headlamp reflector 24.
Before an automobile is released to the consumer, the movable reflectors of the headlamp assemblies are adjusted to a desired position so that the headlamp beams are properly aimed in both the vertical and horizontal directions. To this end, headlamp adjustors are normally operated at the automobile assembly plant. Once proper vertical and horizontal aiming of the headlamps are attained and before the automobile is released to the consumer, vertical and horizontal indicators on each headlamp adjustor are manipulated to provide a visual indication that each movable reflector is in the desired, or "zero", position. The indicators either naturally transmit, or are adjusted in some manner in order to transmit, a visual indication of the zero position. Thereafter, if a movable reflector moves from its desired position, due, for example, to vibration, jarring, or the vehicle being in an accident, a mechanic can use the visual indication to determine that the movable reflector is no longer in its desired position. Then, the mechanic can operate the headlamp adjustors in order to return the horizontal and vertical indicators to the zero positions, which should properly re-align the reflector.
The Department of Transportation of the United States Government has set forth specific guidelines dealing with vehicle headlamp aiming and indicating mechanisms in both the horizontal and vertical directions. The guidelines set forth the degree of accuracy which is required of horizontal and vertical indicators. It is advantageous to provide a headlamp adjustor which is low cost, easy to use, easy to make, and which meets the government guidelines.